A THERMAL MASS FLOW MONITOR FOR CONTINUOUS EMISSIONS MONITORING SYSTEMS (CEMS)

摘要

This paper describes a thermal flow monitor that meets the challenges of the demanding CEMS flow monitoring application. The How Monitor6 uses an array of thermal sensors which monitor the mass flow rate of the stack gas in typically 12 or 16 equal areas, at locations identical to those used in the EPA type-S pitot tube reference method. Since both methods measure the mass flow at the same points, the Flow Monitor provides uninterrupted passage of Relative Accuracy Test Audits, even in the highly non-uniform flows characterizing most CEMS monitoring locations. In essence, the Flow Monitoris an automated CEMS reference method. Long-term availability and accuracy are enhanced because the How Monitor performs daily calibration error tests of the active theimal sensing elements; minimizes interference by participates via a unique automatic sensorcleaning technology;and accurately compensates for temperature variations by means of a new microprocessor-based digital sensor drive. Relative to other candidates, the How Monitor has the lowest total cost of ownership - the only objective method of comparison.